Catalyst composition and olefin polymerization using same

ABSTRACT

Novel metal complexes, particularly chromium complexes, which contain at least one tridentate ligand are disclosed and prepared. Olefins, particularly ethylene, can be reacted to form butene and/or other homo- or co-oligomers and/or polymers with high α-olefin concentrations by contacting a metal catalyst which contains a transition metal, particularly chromium, complexes having per metal atom at least one tridentate ligand with N, O, or N and O coordinating sites.

FIELD OF THE INVENTION

[0001] This invention relates to novel metal complexes, particularlychromium complexes, which contain at least one tridentate ligand foreach metal. This invention also relates to an improved olefinpolymerization process catalyzed by a catalyst composition, whichcomprises such novel metal complexes. The polymerization process isparticularly useful for making 1-butene and a wide range of oligomericand polymeric products having high α-olefin concentrations.

BACKGROUND

[0002] Many linear olefins, particularly linear α-olefins, typicallyhave a variety of valuable uses. For example, α-olefins, such as1-hexene, can be used in hydroformylation (so-called “OXO” process) toproduce oxygenated products like alcohols and aldehydes. In addition tofinding uses in specialty chemicals or as intermediates, α-olefins alsocan be used in polymerization processes as either a monomer orco-monomer to prepare polyolefins, or other polymers. For example, ithas been widely reported that 1-octene can form polymers or co-polymers,which may be used as effective drag reducing agents for transportinghydrocarbons in pipelines, It is therefore desirable to control thelinearity of the product, or produce linear olefins, particularly linearα-olefins, in most oligomerization or polymerization processes.

[0003] It is well known that mono-olefins, particularly lower α-olefins,particularly ethylene, propylene, and 1-butene can be oligomerized(including dimerized and trimerized) and/or polymerized by usinghomogeneous or heterogeneous catalyst systems comprising compoundsderived from transition metals such as titanium, zirconium, vanadium,chromium, nickel and/or other metals, either unsupported or on a supportsuch as alumina, silica, silica-alumina, titania, other refractory metaloxides, and other similar materials. Even diene monomers such as1,3-butadiene may be oligomerized or polymerized to give variousproducts such cyclooctadienes. These polymerization catalyst systemsfrequently are used with an organometallic co-catalyst, such asorganoboron, organoaluminum and/or organotin compounds.

[0004] Many catalyst systems are usually not very selective in theproduction of oligomeric or polymeric olefinic products in terms ofmolecular weight distribution, linearity of the carbon-carbon backbone,branching, location of the double bond(s) in the product, andincorporation of co-monomers, if any, into the product. Some reportedhomogeneous organometallic catalyst systems tend to have loweractivities, higher consumptions of co-catalysts, but they can producelower molecular weight oligomers or polymers with a narrow molecularweight distribution.

[0005] As a result, there is always a need of improving the catalystsystems to have better catalytic properties in terms of controllingspecific oligomerization or polymerization of specific olefins ordiolefins to produce products with the desired or targeted physical andchemical properties.

SUMMARY OF THE INVENTION

[0006] It is one objective of the present invention to provide apolymerization process for making a product, the polymerization processcomprises contacting at least one olefin in a feed, with or without amedium, with a catalyst and a co-catalyst, followed by recovering theproduct, wherein the catalyst comprises a metal-tridentate ligandcomplex comprising a metal, preferably a transition metal, one or moretridentate ligands (such as FORMULA A) having at least two differentelements for the three coordinating sites in each tridentate ligand, theelements are independently selected from the group consisting ofnitrogen, phosphorus, oxygen, and sulfur, and wherein themetal-tridentate ligand complex has a formula as FORMULA B.

[0007] It is another object that the olefin to be polymerized includes,but is not limited to, mono-olefins (α-olefins and internal olefins;linear and branched olefins) like ethylene, propylene, 1-butene,cis-2-butene, trans-2-butene, 1-pentene, 3-methyl-1-pentene,4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, vinylcyclohexane,cyclopentene, methylcyclopentene (1-, 2-, 3- or mixtures), 1-octadecene,and mixtures of mono-olefins; dienes like 1,3-butadiene, isoprene,1,4-pentadiene, 1,3-hexadiene, 1,4-hexadiene and 1,5-hexadiene,4-vinylcyclohexene, vinylnorbornene, norbornadiene, and mixtures ofdienes; vinyl-aromatic compounds such as 1- or 2-vinylnaphthalene, 2- or4-vinylpyridine, styrene and substituted styrenes like o-methylstyrene,m-methylstyrene, p-methylstyrene, p-ethylstyrene, divinylbenzene, andp-t-butylstyrene; and mixtures thereof; and mixtures of mono-olefins,dienes and/or vinyl-aromatic compounds.

[0008] It is a further object to provide a catalyst composition whichcomprises a metal-tridentate ligand complex having a structure ofFORMULA B, wherein M consists essentially of an element selected fromthe group consisting of manganese, chromium, vanadium, nickel, andmixtures thereof; the co-catalyst comprises one or more aluminum alkylcompounds or organoboron compounds, or mixtures thereof; and the productcomprises α-olefins, which can be linear, branched, or mixtures thereof.In another embodiment, the product can be characterized by havingSchulz-Flory constants (K) in the range of from about 0.4 to about 0.98,preferably from about 0.5 to about 0.9, more preferably from about 0.55to about 0.8.

[0009] It is another object to provide an ethylene dimerization processfor making 1-butene, the dimerization process comprises contactingethylene in a feed, with or without a medium, with a catalyst and aco-catalyst, followed by recovering 1-butene, wherein the catalystcomprises a metal-tridentate ligand complex comprising a transitionmetal, one or more tridentate ligands (such as FORMULA A) havingnitrogen for all three coordinating sites in the tridentate ligand, andwherein the metal-tridentate ligand complex has a formula as FORMULA B.Depending on R¹¹ and R¹⁵, high 1-butene purity (in excess of 98%,preferably in excess of 99% or higher, among the butene isomers) may beobtained.

[0010] Another object of the present invention to provide a catalystcomposition which comprises a metal-tridentate ligand complex comprisinga structure of FORMULA B.

[0011] It is a further object to provide a catalyst composition whichcomprises a metal-tridentate ligand complex comprising a structure ofFORMULA B, wherein Q¹, and Q² are nitrogen, Q³ is oxygen, and R⁴ doesnot exist; R¹ and R³ are independently selected from C₁ to C₅ alkylgroups; R² is selected from 1-ring aryl groups; R⁵ R⁶, and R⁷ areindependently selected from H and C₁ to C₅ alkyl groups; L is selectedfrom F, Cl, Br, I and mixtures thereof; and q is 2.

[0012] It is another object of the present to provide a chromiumchloride complex containing6-[1-{(2,6-dimethylphenyl)imino}ethyl]-2-acetylpyridine.

[0013] It is yet another object of the present to provide a chromiumchloride complex containing6-[1-{(2,6-diisopropylphenyl)imino}ethyl]-2-acetylpyridine.

[0014] It is still another object to provide a method for making themetal complexes with suitable transition metal starting materials andsuitable ligands under conditions effective to produce such complexes.

[0015] It is yet another object to provide a method for making thesuitable tridentate ligands, which are useful for making the metalcomplexes.

[0016] Another object is to provide a multi-component catalyst systemcomprising (a) at least one first component consisting essentially of anethylene or propylene dimerization or trimerization catalyst comprisinga metal-tridentate ligand complex described herein, such as FORMULA Bcontaining a first transition metal, and with nitrogen for all threecoordinating sites, and (b) at least one second component consistingessentially of an ethylene or propylene polymerization catalyst such asa Ziegler-Natta catalyst, a precursor of the Ziegler-Natta catalyst, ametallocene, a precursor of the metallocene, and mixtures thereof. Thesecond component contains a second transition metal. It is preferred touse one or more co-catalysts such as organometallic compounds with themulti-component catalyst system to produce ethylene or propylenepolymers.

[0017] A further object is to provide an olefin polymerization processusing a multi-component catalyst system, an organometallic co-catalyst,and the olefin being selected from ethylene, propylene and mixturesthereof in a feed under condition effective to produce polymers, whereinthe multi-component catalyst system comprises (a) at least one firstcomponent consisting essentially of an ethylene or propylenedimerization or trimerization catalyst, which comprises ametal-tridentate ligand complex described herein, such as FORMULA B andcontaining a first transition metal, with nitrogen for all threecoordinating sites, and (b) at least one second component consistingessentially of an ethylene or propylene polymerization catalyst such asa Ziegler-Natta catalyst, a precursor of the Ziegler-Natta catalyst, ametallocene, a precursor of the metallocene, and mixtures thereof. Thesecond component contains a second transition metal. The polymers arecharacterized by being a product selected from the group consisting ofpolyethylene (PE), low density polyethylene (LDPE), linear low densitypolyethylene (LLDPE), polypropylene (PP), wax, and mixtures thereof.

[0018] Other additional objects and advantages will become apparent toand appreciated by those skilled in the art by reading the disclosuresherein.

DETAILS OF THE INVENTION

[0019] The present invention relates to novel metal-ligand, particularlymetal-tridentate ligand complexes, the method for making such complexes,and olefin polymerization processes using catalysts comprising suchcomplexes. The present invention also relates to a novel multi-componentcatalyst system, which system comprises (a) at least one first componentconsisting essentially of such a metal-multidentate ligand complex and(b) at least one second component consisting essentially of at least oneZiegler-Natta catalyst or its precursor or a metallocene or ametallocene precursor or mixtures thereof; and a polymerization processusing such multi-component catalyst in the presence of an organometallicco-catalyst. For the instant invention and disclosure, the term“polymerization” is used interchangeably, unless otherwise specificallyspecified or claimed, with the term “oligomerization” to encompassgenerally (co-)dimerization, (co-)trimerization, homo- orco-oligomerization, and homo- or co-polymerization of one or moreolefins (alkenes), vinyl aromatics, and/or diolefins to form(co-)dimers, (co-)trimers, homo- or co-oligomers and/or homo- orco-polymers of the olefin(s) in a feed.

[0020] Suitable metal-ligand complexes comprise a metal, a bidentate,tridentate or multidentate ligand, other ligands/moieties/counter-ionsto balance the electrical (ionic) charge so that the whole complex isneutral and/or the formal electron count is satisfied, and optionallysolvent molecules. Two or more metal atoms, same or different and withor without direct metal-metal bonds may be present in a complex.

[0021] Unless a specific ligand is used or referred to, the word“multidentate” is used to denote a ligand having two, three or morecoordinating sites. Many ligands having different number and/or type ofcoordinating sites can be used for the present invention. Tridentateligands are preferred for the present invention. It is more preferred tohave at least two different elements (for instance, N and O) for thethree coordinating sites of the three per tridentate ligand. Forethylene dimerization to 1-butene, it is preferred to have nitrogen forall of the three coordinating sites; it is more preferred to have eitherR¹¹ or R¹⁵ being selected from the group consisting of methyl (Me),ethyl (Et), n-propyl (nPr), iso-propyl (iPr), and n-butyl (nBu). Formaking wax, it is preferred to have either R¹¹ or R¹⁵ being a t-butylgroup.

[0022] A more preferred tridentate ligand has the following FORMULA A.

[0023] wherein

[0024] Q¹, Q², and Q³: independently selected from O, S , N, and P;

[0025] R¹ and R³: independently selected from H, C₁ to C₂₀ alkyl groups,1-, 2- or 3- (i.e. 1-3) ring aryl groups and substituted aryl groups;

[0026] R² and R⁴: if Q² or Q³ is O or S, none

[0027] if Q² or Q³ is either N or P, independently selected from H, C₁to C₂₀ alkyl groups, 1-, 2- or 3-ring aryl groups and substituted arylgroups;

[0028] R⁵, R⁶, and R⁷: independently selected from H, C₁ to C₂₀ alkylgroups; and R⁷ does not exist if the carbon to which it is attached isnot present.

[0029] It is understood that with or without R⁷ and the associate carbonto which it is attached, the ring containing Q¹ is characterized by andshould have some aromatic characteristics. For instance, Q¹ may beoxygen and the ring is based on a five-membered ring furan structure.

[0030] Depending primarily on the starting materials for the metal(s)and the nature of the multidentate ligands, there may be other ligandsor moieties or ions present in the complex to balance the electrical(ionic) charges and/or formal electron counts. For instance, if chromium(II) chloride, or CrCl₂, is used as the starting material for chromium,chloride will be present in the metal-ligand complex. The number andtype of the ligands present may vary, depending on the oxidation stateof the metal in the starting material, whether there is any redoxreaction taking place, whether the multidentate ligand is used in anionic form with its own counter-ions, the number of metals in thecomplex, and other reaction conditions. There may be other reactants,either organic or inorganic, such as acids, salts, bases, and mixtureswith different ions present in the reaction, which may end up in thefinal product.

[0031] “L” can be any anions or neutral molecules such as CO. Somenon-limiting examples of “L” include CO, H, hydroxide (OH), halides andpseudo-halides, chlorate, chlorite, phosphate, phosphite, sulfate,sulfite, nitrate, amides, alkoxides and their analogues (including thosederived from glycols, thiols and phenols), carboxylates (includingdicarboxylates and substituted carboxylates such as 2-ethylhexanoate andtriflates), hydrocarbyls like alkyls (such as methyl, ethyl, andothers), alkenyls, aryls (such as phenyl, methylphenyls, and the like),and mixtures thereof. More examples are further disclosed below inassociation with FORMULA B.

[0032] Because the complex preparation is generally more convenientcarried out in a solution, there may be one or more solvents presentduring the reaction and/or in the final complex. If one of the reactantsis a liquid or the reaction is conducted in a melt-phase, a solvent isnot needed for this convenience. As long as a solvent or solvent mixturedoes not interfere with the metal-multidentate ligand complex formation,it can be used. Depending on the nature of the solvent, the metalcomplex and the recovery methods/conditions, one may find that there isno solvent in the recovered complex. It is also possible to find bychemical analyses that the number of solvent molecules per metal may befractional.

[0033] Examples of a suitable solvent include both organic and inorganicsolvents and their mixtures, such as alcohols (methanol, ethanol, 1- or2-propanol, sec-butanol, n-butanol, t-butanol, ethylene glycol,propylene glycol, mixtures thereof, or mixtures with water), ethers(dimethyl ether, diethyl ether, methyl ethyl ether, tetrahydrofuran orTHF, tetrahydropyran, 1,3-dioxane, 1,4-dioxane and mixtures thereof),glycol ethers, esters (methyl acetate, ethyl acetate, etc), thioethers,halogenated hydrocarbons (such as CFC's [chlorofluoro hydrocarbons],methyl chloride, methyl bromide, methyl iodide, dichloromethane,dibromomethane, chloroform, ethylene dichloride and others), aliphaticand aromatic hydrocarbons, and mixtures thereof. Many of these solvents,such as oxygenated solvents (an ether like THF is an example) can becharacterized as Lewis base solvents (i.e. electron pair donatingsolvents). Additional examples are disclosed below in FORMULA B.

[0034] A metal-tridentate ligand complex suitable for the presentinvention is of the following general FORMULA B:

[0035] wherein

[0036] Q¹, Q², and Q³: independently selected from O, S, N, and P;

[0037] R¹ and R³: independently selected from H, C₁ to C₂₀ alkyl groups,1-, 2- or 3- (i.e. 1-3) ring aryl groups and substituted aryl groups;

[0038] R² and R⁴: if Q² or Q³is O or S, none

[0039] if Q² or Q³is either N or P, independently selected from H, C₁ toC₂₀ alkyl groups, 1-, 2- or 3- (i.e. 1-3) ring aryl groups andsubstituted aryl groups;

[0040] R⁵, R⁶, and R⁷: independently selected from H, C₁ to C₂₀ alkylgroups;

[0041] M: a first transition metal selected from the group consisting ofCr, Mn, V, Ni, Ti, Zr, Hf, Ta, and mixtures thereof;

[0042] L: each L independently selected from the group consisting of F,Cl, Br, I, C₁ to C₂₀ alkyl, C₅ to C₁₄ aryl, nitrate, OR²¹, OC(═O)R²²;R²³; CN; SCN, CO, H, wherein R²¹, R²², and R²³ are independentlyselected from the group consisting of H, C₁ to C₂₀ alkyl groups,substituted alkyl groups, 1-, 2- or 3-ring aryl groups, substituted arylgroups, and silyl groups;

[0043] solvent selected from the group consisting of ethers, polyethers,esters, alcohols, halogenated hydrocarbons, and mixtures thereof;

[0044] q 0-5 (integer) to balance overall electrical charge

[0045] m 0-10 (integer or fractional).

[0046] As understood from the chemical formula/structure of FORMULA B,the metal complex must comprise at least one metal, preferably a firsttransition metal and at least one tridentate ligand. As discussedearlier, the number of other ligands (L) would depend on the netelectric (used interchangeably with ionic) charge of the M-Ligand so asto make the entire formula neutral. Also as discussed earlier, thenumber of solvent molecules may vary, depending on the complex,solvent(s), preparation method and many other factors and “m” need notbe an integer as determined by chemical analyses. In other words, “m”may be fractional (per metal).

[0047] The scope of the present invention encompasses many differentmetals, M, particularly transition metals, such as titanium, zirconium,hafnium, vanadium. niobium, tantalum. chromium, manganese, iron, nickel,cobalt, and mixtures thereof. It is preferable that M consistsessentially of an element selected from the group consisting ofchromium, manganese, vanadium, and mixtures thereof. Chromium is a morepreferred metal.

[0048] Many different sources of these metals may be used to prepare themetal-ligand complexes. These sources include, as discussed earlier,metal halides, pseudo halides, carboxylates, alkoxides, phenoxides,nitrates, sulfates, phosphates, chlorates, organometallic compounds,metal carbonyls, metal clusters and mixtures thereof. Differentoxidation states may be used. For instance, many of these materials maybe purchased from commercial sources such as Aldrich Chemical Company,Fluka Chemical Company, Alfa AESAR Chemical Company, etc.

[0049] More specifically for chromium (oxidation states from 0 to VI),the following materials may be used: chromium(II) chloride,chromium(III) chloride, chromium(II) fluoride, chromium(III) fluoride,chromium (II) bromide, chromium(III) bromide, chromium(II) iodide,chromium(III) iodide, chromium(II) acetate, chromium (III) acetate,chromium(III) acetylacetonate, chromium(II) 2-ethylhexanoate, chromium(II) triflate, chromium(III) nitrate, Cr(CO)₆, and mixtures thereof.

[0050] As mentioned briefly above, L can be any suitable anion orneutral molecule. If one or more “L's” are needed to balance the chargeof FORMULA B to zero, then each “L” is independently selected from thegroup consisting of CO, H, halides (F, Cl, Br, I,), nitrate, alkoxidesor phenoxides (OR²¹), carboxylates [OC(═O)R²²], R²³, CN, SCN, and CO.R²¹, R²², and R²³ are independently selected from the group consistingof H, C₁ to C₂₀ alkyl groups, substituted alkyl groups, 1-, 2- or 3-ringaryl groups, substituted aryl groups and other hydrocarbyl groups suchas alkenyl groups. The substituents on the alkyl or aryl groups include,but are not limited to alkyls, aryls, halides, silyl groups, aminogroups, alkoxy groups and mixtures thereof. In addition, L can also beselected from hydrocarbyls such as alkyl, alkenyl, or aryl groups.Examples of suitable alkyl groups include, but are not limited to C₁ toC₂₀ linear or branched alkyls, such as methyl, ethyl, n-propyl,isopropyl, n-butyl, iso-butyl, t-butyl, sec-butyl, 1-octyl groups andothers. C₃ to about C₂₀ linear or branched alkenyl groups also may beused. Examples of suitable aryl groups include, but are not limited toC₅ to C₁₄ aryls such as 4-pyridyl, 2-pyridyl, phenyl, p-methylphenyl,o-methylphenyl, etc. It is preferred to have halogens as L. It is morepreferred the L is or consists of or consists essentially of Cl.

[0051] If two or more L's are needed, then they can be independentlyselected from all of those described and disclosed above, or frommoieties containing two or more such groups. For instance, if two L'sare needed or preferred, then a glycol type (LL), i.e. —O—CH₂—CH₂—O— or—O—CH₂—CH(CH₃)—O— can be used. It is also within the scope of theinvention to have mixed (LL′) type where the chelating groups are notidentical. The above propylene glycol type is one example. Otherexamples include moieties with mixed alkoxides with phenoxides and/orcarboxylates.

[0052] It is preferred that Q¹ is nitrogen (N). Hydrogen and C₁ to C₅alkyl groups such as methyl or ethyl are preferred, independently, forR⁵, R⁶, and R⁷. More preferably, R⁵, R⁶, and R⁷ are all H.

[0053] Q¹, Q², and Q³ can all be nitrogen (N) in FORMULA B. In apreferred embodiment, not all of Q¹, Q², and Q³ are the same,particularly for making waxes or polyethylenes. It is more preferred tohave (a) N for Q¹, N for Q², and O for Q³; or (b) O for Q¹, N for Q²,and O for Q³.

[0054] Preferably Q² is nitrogen (N). When Q¹ and Q² are both nitrogen,it is preferred that Q³ is oxygen or sulfur, except for ethylenedimerization to high purity 1-butene or 2-butenes or mixtures thereof.In this case, R⁴ does not exist (i.e. none) to satisfy the valencerequirement of oxygen or sulfur. Ethylene can be dimerized to butene byusing the present invention. For ethylene dimerization to 1-butene inexcess of 98%, preferably in excess of 99% or higher purity among buteneisomers, it is preferred to have Q¹, Q², and Q³ all being nitrogen; andpreferably R² and R⁴ are phenyl and the corresponding R¹¹ is preferredto be independently selected from the group consisting of methyl, ethyl,n-propyl or isopropyl. For ethylene dimerization to butenes (1-butene,cic-2-butene, trans-2-butene mixture), it is preferred to have Q¹, Q²,and Q³ all being nitrogen; and preferably R² and R⁴ are both phenyl andthe corresponding two R¹¹ groups are preferably hydrogen. (see FORMULA Cbelow)

[0055] Regardless which elements are selected for Q² and Q³, it ispreferred to have selected from C₁ to C₅ alkyl groups, 1-ring aryl andsubstituted aryl groups (i.e. phenyl groups) selected independently forR¹ and R³. Methyl group is more preferred for both R¹ and R³.

[0056] If either or both of Q² and Q³ are nitrogen, then it is preferredto have phenyl groups for R² and/or R⁴ attached to the nitrogen and thephenyl groups, selected independently for Q² and/or Q³, are shown asfollows (FORMULA C)

[0057] wherein

[0058] R¹¹, R¹², R¹³, R¹⁴, and R¹⁵ are individually selected from H, C₁to C₂₀ alkyl groups, substituted C₁ to C₂₀ alkyl groups, 1-3 ring arylgroups, substituted 1-3 ring aryl groups, F, Cl, Br, I, amino groups,silyl groups such as Si(CH₃)₃, Si(phenyl)₃, and the like. Many othersubstituents such as nitro groups can also be used for making themetal-tridentate ligand complexes. However, if the complexes are used ascatalysts for polymerization reactions, all of the above-mentioned R'sshould not have functional groups that would interfere with thepolymerization reactions themselves or other components such asco-catalysts, if present. It is preferred to have H for R¹², R¹³, andR¹⁴. It is also preferable to have a C₁-C₅ alkyl group or H for eitheror both of R¹¹ and R¹⁵. More preferred R¹¹ and R¹⁵ are selectedindependently from the group consisting of H, methyl, ethyl, n-propyl,iso-propyl, and n-butyl groups. As already discussed, Q¹, Q² and Q³ arepreferably all nitrogen and only one of R¹¹ and R¹⁵ is H when ethylenedimerization to 1-butene (in excess of 98%, or preferably in excess of99% or even higher purity) is the preferred polymerization reaction.When 2-butenes or butene mixtures are the preferred ethylenedimerization products, both R¹¹ and R¹⁵ are preferred to be H.

[0059] When the metal M is selected from the group consisting ofmanganese, chromium, vanadium, and mixtures thereof, it is preferred tohave H, methyl, iso-propyl, and/or n-butyl groups for both R¹¹ and R¹⁵in order for the complexes to be better catalysts, particularly ascatalysts for ethylene polymerization or co-polymerization in thepresence of a co-catalyst such as aluminum alkyls, aluminum alkylhalides, alumoxanes such as MAO or MMAO (modified MAO, some arecommercially available products from Akzo Nobel in heptane solutions.).

[0060] FORMULA B is a preferred embodiment of the present invention. AsFORMULA A INDICATES, it is also within the scope of the presentinvention that a five-membered ring containing Q¹ may be used as part ofthe tridentate ligand. In this case, R⁷ and the carbon to which it isattached in FORMULA B do not exist. It is still contemplated that thefive-membered ring portion possesses aromatic characteristics. Dependingon Q¹, the electrical (ionic) charge of the entire metal complex has tobe balanced to zero with a proper number of “L's” present.

[0061] Another embodiment of the present invention provides amultidentate ligand with 2, 4, 5 or 6 coordinating atoms. While thethree coordinating atoms in FORMULA B are more or less on the sameplane, i.e. co-planar, this may not be the case for all of thecoordinating atoms in a tetra-, penta-, or hexa-dentate ligand.

[0062] As already mentioned briefly, a preferred solvent includes, butis not limited to, coordinating solvents (i.e. Lewis base type solventsor electron pair donating solvents), particularly polar oxygenatedsolvents such as alcohols, ethers, esters, ketones, or mixtures. Somewater may be present with the alcohols, ethers, glycols, or otherwater-miscible organic solvents. Examples of suitable polar oxygenatedsolvents include, but are not limited to, dimethyl ether, diethyl ether,methyl ethyl ether, monoethers or diethers of glycols such as dimethylglycol ether, furans, dihydrofuran, substituted dihydrofurans,tetrahydrofuran (THF), tetrahydropyrans, (1,3 and/or 1,4-) dioxanes,methyl acetate, ethyl acetate, methyl ethyl ketone, acetone, and thelike and mixtures thereof. Acyclic or cyclic polyethers such aspoly(ethylene glycol) ethers, crown ethers (such as 12-crown-4 or18-crown-6) and their mixtures can also be used even though some of themmay be much more expensive than others.

[0063] THF is a more preferred solvent, particularly when CrCl₂ is usedas a starting material with6-[1-{(2,6-dimethylphenyl)imino}ethyl]-2-acetylpyridine and6-[1-{(2,6-diisopropylphenyl)imino}ethyl]-2-acetylpyridine as theligands. Other polar solvents such as 1,4-dioxane, tetrahydropyran,halogenated hydrocarbons (chloroform or dichloromethane), thioethers,and the like also may be used alone or as mixtures between themselves orwith other solvents, particularly those disclosed herein.

[0064] The following general procedure may be used to prepare the metalcomplexes. A first amount of a metal starting material, such as ahalide, and a second amount of a ligand, such as6-[1-{(2,6-dimethylphenyl)imino}ethyl]-2-acetylpyridine are mixed in asuitable solvent under conditions effective to produce the product. Themixture is thoroughly mixed with proper agitation or gas purging for aperiod from one minute to 30 days. Then, optionally the mixture may belet stand for an additional one minute to thirty days without agitation.If the product is an insoluble solid in the reaction solvent, it isfiltered and optionally washed with the same solvent or another solvent,preferably a more volatile one. The washed product is then placed undervacuum or in a flowing gas condition to remove all the volatiles. If theproduct is soluble in the reaction solvent under the conditions, one caneither remove part or all of the solvent, and/or cool the reactionmixture to a lower temperature to precipitate the product solid followedby filtration and optional washing. The solid can also be recovered byremoving the solvent by other techniques such decantation known to thoseskilled in the art. The product is then weighed to determine yield andcharacterized by chemical analyses, NMR and/or ICP to determine itschemical composition and structure. In the rare event that the complexis a liquid at room temperature, the product can be recovered orpurified by distillation, chromatography or other means known in theart.

[0065] As shown in FORMULA B, it is most likely that themetal-tridentate ligand complex has a ligand to metal molar ratio of1:1. For preparation of the complex, the molar ratio of the ligand tothe metal (whatever the starting material may be) should be in the rangeof 1:10 to 10:1; preferably 1:5 to 5:1; more preferably 1:2 to 2:1.Availability, costs, desired product, and productseparation/purification are the major factors to be considered forselecting a suitable molar ratio.

[0066] The complex formation reaction can be carried out at atemperature in the range of from about −20° C. to about 150° C.,preferably form about 0° C. to about 90° C., and more preferably fromabout 15° C. to about 50° C. The pressure is normally not a criticalfactor. It is convenient to use ambient pressure, but sub- orsuper-atmospheric pressures may be used. Some of the starting materialsand/or products may be air and/or moisture sensitive. It is thereforepreferred to carry out the reaction and/or the product recovery and/orthe product purification steps in a dried atmosphere such as nitrogen,argon, helium, neon, krypton, methane, ethane, propane, and mixturesthereof. If there are no other concerns, air, carbon monoxide, carbondioxide, hydrogen may also be used individually, or as mixtures thereof,or as mixtures with inert gases or other gases. It may also be easier tokeep moisture and oxygen out by having a reactor or reaction systempressure slightly higher than the ambient (atmospheric) pressure.

[0067] If it is desirable to support the metal complex on a carrier,there are many inorganic and/or organic carriers within the scope of thepresent invention. The selection depends on the nature of the metalcomplex, the co-catalyst if any, the desired polymerization reaction andother similar factors. It is preferred that the support provide somebenefits to the catalyst system chemically or catalytically, but this isnot required. There may be other reasons to select a particular support,for instance easier product purification, lower cost, cheapermanufacturing process, etc. Inorganic carriers suitable for the presentinvention include, but are not limited to, crystalline or amorphoussilicas (including those disclosed in U.S. Pat. No. 6,107,236),crystalline or amorphous aluminas, zeolites (both natural and syntheticones such as ZSM-5, ZSM-11, etc), crystalline or amorphoussilicoaluminas, silicoaluiminophosphates (SAPOs), metalaluminophosphates(MEAPOs), aluminophosphates (ALPOs), titanium oxide (titania), zirconiumoxide (zirconia), magnesium oxide, magnesium chloride, manganesechloride, and the like and mixtures thereof. Some typical examples ofsuitable supports can be found in “Heterogeneous single site catalystsfor olefin polymerization” Gregory G. Hlatky, Chemical Reviews, 100, pp1347-1376 (2000).

[0068] A metal-multidentate ligand complex may be placed on the supportsby a number of known methods. The support can be present during or afterthe metal complex is made from the starting materials. Non-limitingexamples include incipient wetness, in-situ mixing, solutionimpregnation, dry-mixing/admixing/blending, ion-exchange, sublimation,co-precipitation, and combinations and/or repetitions thereof.

[0069] As already mentioned hereinabove, the present invention alsorelates to a novel multi-component catalyst system for olefin,particularly ethylene or propylene or mixtures thereof, polymerizationprocess. This multi-component catalyst system comprises (a) at least onefirst component consisting essentially of one or more ethylene orpropylene dimerization and/or trimerization catalyst comprising themetal-multidentate ligand complexes, particularly the chromium basedcomplexes as described herein (such as those encompassed by FORMULA B)and preferably all coordinating sites are nitrogen; and (b) at least onesecond component consisting essentially of an olefin polymerizationcatalyst selected from the group consisting of Ziegler-Natta catalyst,its precursor, a metallocene or metallocene precursor, a secondmetal-tridentate ligand complex wherein it is different from the one(s)used in (a) and/or not all three coordinating sites are the same, andmixtures thereof. This catalyst system, supported or unsupported, may beused preferably with a co-catalyst containing at least oneorganometallic compound as disclosed herein to polymerize olefins,particularly α-olefins like ethylene or propylene or mixtures ofethylene and propylene to a product. The product may be wax, PE, PP,LDPE, LLDPE, and the like, and mixtures thereof. Without being bound bya particular theory, it is expected that the first component willdimerize or trimerize ethylene and/or propylene to butene, pentene,hexane, heptane, octane and/or nonene. These olefins serve asco-monomers during polymerization of ethylene and/or propylene catalyzedby the second component. Of course, it is also expected thatoligomerization of these C₄-C₉ olefins with or without additionalethylene and/or propylene incorporated can also take place. Depending onthe catalyst system and reaction conditions selected, products ofvarious characteristics can be produced in accordance with thedisclosures of the present invention.

[0070] Examples of suitable ethylene and/or propylene dimerizationan-d/or trimerization catalyst include, but are not limited to, thosecomprising a metal-tridentate ligand complex such as those representedby FORMULA B, wherein preferably the metal is selected from the groupconsisting of Cr, V, Mn, Ni, and/or mixtures thereof. It is morepreferred that the metal M is or consists essentially of chromium (Cr),Q¹, Q², and Q³ are all nitrogen (N), both R² and R⁴ have the structureof FORMULA C (i.e. phenyl groups), R¹¹ is preferably selected from H,methyl, ethyl, n-propyl, iso-propyl, and n-butyl groups, and R¹⁵ is H.

[0071] Examples of suitable Ziegler or Ziegler-Natta type catalysts forthe second component include, but are not limited to those disclosed inGregory G. Hlatky, Chemical Reviews, 100, pp 1347-1376 (2000). Thecatalysts can be either “metallocene” or “non-metallocene” type. Someexamples can be found in Gibson et al, Angew. Chem. Int'l Ed., 38, 428(1999); and Pullkat et al, Catal. Rev.-Sci. Eng., 41(3&4), 389-428(1999).

[0072] Examples of metallocenes or metallocene precursors suitable foruse as the second component of the multi-component catalyst systeminclude, but are not limited to those based on cyclopentadienyl ormodified cyclopentadienyl ligands. Non-liming examples can be found inmany publications such as Waymouth et al, Chemical Reviews, 98,2587-2598 (1998); Alt et al, J. Mol. Cat. A: Chemical 165, 23-32 (2001);Alt et al, Chem. Rev., 100, 1205-1222 (2000); and Ittel et al, Chem.Rev., 100, 1169-1204 (2000).

[0073] The metal-ligand complex of the present invention as disclosedherein with or without a support can be used to effect polymerization ofolefins, particularly in the presence of a co-catalyst. It should berepeated again that, as already defined earlier, the term polymerizationis used herein broadly to include dimerization, trimerization, and/oroligomerization. Thus, the products could be dimers, trimers, oligomers(some of them are described herein as wax or waxes which contain abouttwenty to about sixty or more carbons), polymers and/or mixturesthereof. Under suitable conditions, the products obtained arecharacterized by having a Schulz-Flory constant (K) in the range of fromabout 0.4 to about 0.98, preferably from about 0.5 to about 0.9, morepreferably from about 0.55 to about 0.8.

[0074] The multi-component catalyst system is also useful inpolymerizing olefins, particularly lower alpha-olefins in the presenceof an organometallic co-catalyst. While not bound by a particulartheory, it is believed that the ethylene and/or propylene dimers and ortrimers produced by the first component are incorporated asco-monomer(s) into the polymer products produced by a co-polymerizationcatalyzed by the second component polymerization catalyst. The secondcomponent can be mixed with the first component followed by contactingwith a suitable co-catalyst; or the second component can be added, withor without additional co-catalyst, to the polymerization reactor aftersome initial reaction (such as ethylene or propylene dimerizationreaction) has already taken place. When the multi-component catalyst isused and the olefin is selected from ethylene and propylene, the productis usually characterized by being a polyethylene (PE), low-densitypolyethylene (LDPE), linear low density polyethylene (LLDPE),polypropylene (PP), waxes, and the like, and mixtures thereof. Theproducts are particularly characterized by having branching along thepolymer chain. Such branching may be identified or characterized bynuclear magnetic resonance (NMR), gas chromatography (GC), thermalproperties, or many other methods known to one skilled in art, which areused to characterize co-polymers.

[0075] For most polymerization reactions, co-catalysts are used forsupported, unsupported metal complexes or mixtures thereof. Manyco-catalysts can be used for the present invention to activate thecatalyst or to provide better polymerization activity/selectivity orother properties. Suitable co-catalysts include, but are not limited toorganometallic compounds (monomeric or oligomeric metal alkyls, metalaryls, metal alkyl-aryls, with or without other moieties such as halideor alkoxide) comprising at least one of the metals selected from thegroup consisting of B, Al, Ga, Be, Mg, Ca, Sr, Ba, Li, Na, K, Rb, Cs,Zn, Cd, and Sn. These are referred to as organoboron, organoaluminum,organogallium, organoberyllium, organomagnesiu, organocalcium,organostrontium, organobarium, organolithium, organosodium,organopotassium, organorubidium, organocesium, organozinc, organocadmiumand organotin compounds respectively. The only requirement in thesecompounds is that there is at least one carbon-metal bond like alkyl-M,aryl-M, and delocalized carbon-containing moiety (for instance acyclopentadienyl group, C₅H₅ ⁻)-M bond. As it will become clear later,there may be other groups such as halide, alkoxide and other similargroups. There also may be more than one metal atom in theseorganometallic compounds. A general character is that they are activeenough to reduce the oxidation states of the metals in themetal-tridentate complex, or metallocene precursor, or Ziegler catalystprecursor, or Ziegler-Natta catalyst precursors. Preferred examples ofsuitable co-catalysts include, but are not limited to organoaluminumcompounds (such as aluminum alkyl compounds, with or without halides,alkoxides or other ligands or moieties), organoboron compounds,organolithium compounds, organotin compounds, and mixtures or solutions(many commercial materials are in solvents such as alkanes or alcohols)thereof. Organoaluminum compounds in all forms are more preferred fortheir chemical properties, physical properties, commercial availability,and costs.

[0076] More specific and preferred, but non-limiting, examples aretrimethylaluminum, triethylaluminum, diethylaluminum chloride,diethylaluminum ethoxide, diethylaluminum cyanide, diisobutylaluminumchloride, triisobutylaluminum, t-butyl alumoxanes, ethylaluminumsesquichloride, alumoxanes such as MAO (methylalumoxane), modifiedmethylalumoxane (MAO which contains other aluminum alkyl species ormoieties), dimethylboron bromide, methylboron dibromide, tributylboron,tributyltin chloride, tetra-n-propyltin, tetra-n-butyltin, and mixturesthereof. These materials can be purchased from commercial sources orprepared in accordance with published methods that are known to thoseskilled in the art. As already mentioned, these materials, particularlythose purchased from commercial sources, may further contain solventslike toluene, hexane, alcohols, etc. These solvents generally do notinterfere with the olefin polymerization reactions of this invention.

[0077] The relative amount of a co-catalyst to a catalyst is the rangeof from about 10,000:1 to about 1:10,000, preferably from about 5,000:1to about 1:5,000, more preferably from about 2,000:1 to about 1:2,000,all being molar ratios. In the case of the multi-component catalystsystem, the relative amount of the first component to the secondcomponent is in the range of from about 0.001:1 to about 1:0.001;preferably 0.01:1 to 1:0.01; more preferably from 0.1:1 to 1 : 0.1; allbeing molar basis. The relative amount of a co-catalyst to the totalamount catalyst in the multi-component catalyst system is the range offrom about 10,000:1 to about 1:10,000, preferably from about 5,000:1 toabout 1:5,000, more preferably from about 2,000:1 to about 1:2,000, allbeing molar ratios.

[0078] The co-catalyst(s) can be added to the metal-bidentate,-tridentate, or multi-dentate complexes (catalyst) in any manner knownin the art. For instance, the catalyst and the co-catalyst can be mixedfirst before bringing in contact with a feed comprising an olefin or anolefin mixture. In the alternative, the co-catalyst can be mixed withthe olefin-containing feed first before this mixture is mixed with themetal-ligand complex catalyst. Many other modifications are possible. Asalready described above, in a multi-component catalyst system, thesecond component, with or without additional co-catalyst, may bepre-mixed with the first component, or it can be added to the reactorafter some or all of the initial dimerization and/or trimerizationreaction of ethylene and/or propylene is completed.

[0079] Many different olefins can be polymerized or co-polymerized(including dimerization, co-dimerization, trimerization,co-trimerization, other oligomerizations or co-oligomerizations) usingthe catalyst system of this invention and all these are within the scopeof this invention. Examples include, but are not limited to ethylene,propylene, 1-butene, cis-2-butene, trans-2-butene, butadiene, isoprene,1,3-pentadiene, 1,4-pentadiene, 1,3-hexadiene, 1,4-hexadiene,1,5-hexadiene, 4-vinylcyclohexene, norbornadiene, ethylidenenorbornene,vinylnorbornene, C₅ and higher olefins such as 1-petene,3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene,1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-octadecene, cyclopentene,methylcyclopentene (1-, or 2-, or 3- and mixtures), vinylcyclohexane,norbornene, vinyl aromatics such as styrene, o-methylstyrene,m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene,p-t-butylstyrene, divinylbenzene, 1-vinylnaphthalene,2-vinylnaphthalene, 2-vinylpyridiene, 3-vinylpyridine, 4-vinylpyridine,and the like, and mixtures thereof.

[0080] The product of the polymerization reaction most often comprises(co-) dimers to polymers, depending on the catalyst, the co-catalyst ifany, the feed and other reaction conditions. In a preferred embodimentof this invention, the product comprises primarily terminal (i.e. α-)olefin products, linear or branched or mixtures thereof. Thedistribution of various compounds in the product depends on the reactionconditions, feed composition as well as the catalyst, includingco-catalyst. It is preferred to have narrow distribution of products,particularly for dimerization and trimerization reactions. Productseparation and purification will be easier if there are fewer compoundsin the product. For ethylene dimerization reactions, a typical productcontains primarily 1-butene. It is preferable to have 1-butene in excessof 98% among the butene isomers. It is more preferable to have 1-buteneof 99% or higher purity among the butene isomers.

[0081] The polymerization process or reaction, as previously defined toinclude (co-) dimerization, (co-)trimerization or other oligomerizationsof one or more olefins, may be carried out in any suitable mode orphysical form. For example, the reaction can be homogeneous,heterogeneous or a combination thereof. The polymerization process maybe carried out in a slurry phase, gas phase, liquid phase,super-critical phase, or the like, and combinations thereof. Thepolymerization can be carried out in a batch mode, continuous mode,semi-continuous mode or any other manners known to one skilled in thetechnology.

[0082] Because of the reactivity of metal-multidentate ligand complexand/or the co-catalyst used for the polymerization reaction or for otherconsiderations, it is generally preferred to carry out in a non-reactiveor inert atmosphere the reactions—complex preparation andrecovery/purification (if any), activation, olefin polymerization, orpost polymerization treatments (such as to deactivate the entirecatalyst system or product recovery/purification). Sometimes it is alsopreferred to have some hydrogen in the system. Certainly, if theproducts or the reaction systems are not affected by oxygen and/or waterand there are no other safety concerns under the reaction conditions,then it is more convenient and cost effective to carry out certainindividual steps in air.

[0083] The polymerization reaction was carried out in a suitable reactorunder conditions effective to produce the desired product. The importantreaction parameters include, but are not limited to, themetal-multidentate ligand complex, the metallocene and/or metalloceneprecursor if used, the co-catalyst, ratio of co-catalyst to thecatalyst, the feed, the medium (i.e. solvent) if one is used, reactiontemperature, reaction time, olefin partial pressure if it is a gas orhas a substantial vapor pressure under the reaction condition,replenishment of consumed olefin if desirable, amount of co-monomer ifpresent, other reactants such as hydrogen desired, reactive impurities(such as oxygen and water) in the reaction system, and the productwork-up procedure.

[0084] If the olefin monomer is a gas under the conditions, such asethylene, then a suitable partial pressure is in the range of from about0.1 psia (0.7 kPa) to about 2,500 psia (17,250 kPa), preferably 0.2 psia(1.4 kPa) to 2,000 psia (13,800 kPa), more preferably from 0.5 psia (3.4kPa) to 1,500 psia (10,300 kPa) Because the total system pressure willdecrease as the gaseous olefin(s) is(are) polymerized or consumed, onecan continue to add more monomer(s) to the reactor at a set rate (suchas a continuous flow of the monomer to the reactor), add differentmonomers, if more than one, at different rates, add more monomer(s) ondemand to maintain a certain system pressure, add a second differentmonomer or monomer mixtures to the reactor, let the system pressuredecrease, any other choices known to those skilled in the art, or acombination thereof. If no additional monomer is needed or desired,gases inert to the reaction mixture may be used to make the necessarypressure.

[0085] The polymerization temperature is in the range of from about 0°C. to about 150° C., preferably from about 10° C. to about 120° C., morepreferably from 20° C. to 75° C. A suitable temperature is determined bya number of factors, such as catalyst stability, catalyst activity, themonomer or monomers to be polymerized or co-polymerized, the propertiesof the co-catalyst, and others.

[0086] The olefin monomer(s) may be pre-mixed or added simultaneously tothe polymerization reactor, or added sequentially to the reactor ormetered into the reactor in some other manner. The olefin monomer(s) canalso be added as needed (on demand) to maintain a certain systempressure. The olefin monomer(s) can also be added continuously atcertain rate. Or, the olefin monomers can also be added at the beginningand then let them be consumed without any additions. All these may bedone at fixed reaction parameters or variable parameters such aspressure ramp or temperature ramp. Combinations of some of these mayalso be used.

[0087] The olefin monomer(s), the metal-ligand complex or themulti-component catalyst system, the co-catalyst (if used), and anyother materials, such as a medium, may be mixed or contacted with oneanother according to the sequences or orders known to those skilled inthe art. Certainly, the first component, the second component, and othercomponents (if any) and the co-catalyst may be brought into contact withone another in any order or sequence or simultaneously.

[0088] The following examples illustrate preparations of exemplaryligands, preparations of certain metal-multidentate ligand complexes,and polymerization of olefins by using catalysts comprising thecomplexes and co-catalyst, and analyses used to characterize differentproducts from these reactions.

EXAMPLE 1

[0089] This example shows a typical preparation method of a tridentateligand like 6-[1-{(2,6-dimethylphenyl)imino}ethyl]-2-acetylpyridine. 3.0g (18.4 mmol) of 2,6-diacetylpyridine and 2.3 ml (18.7 mmol) of2,6-dimethyl aniline were added to a flask with a stirbar and 20 ml ofanhydrous methanol. Several drops of glacial acetic acid were added, andthe reaction was heated with stirring for 3 days at 55° C. The reactionflask was then placed in a freezer at −20° C., resulting in theformation of yellow, needlelike crystals. These crystals were removed byfiltration and washed with cold methanol (yield=1.15 g, 23.5%).

EXAMPLE 2

[0090] The following is one example of demonstrating how a chromiumbased complex—chromium(II)6-[1-{(2,6-diisopropylphenyl)imino}ethyl]-2-acetylpyridine chloride(with THF) was prepared:

[0091] A sample of 1.0 gram of6-[1-{(2,6-diisopropylphenyl)imino}ethyl]-2-acetylpyridine and 382 mg ofchromium chloride (CrCl₂, obtained from Aldrich Chemical Company) weretransferred into a flask in a drybox under argon. Anhydrous tetrahyfuran(THF), about 50 ml, was added to this mixture. The mixture was stirredovernight under argon. The mixture was then allowed to stand for threedays, followed by addition of about 100 ml of n-pentane. A grayishpurple solid was isolated by filtration in air. The filtrate was green.The recovered solid was further washed with n-pentane and dried. Totalyield was 1.237 grams (90% of theoretical yield).

[0092] This metal complex was used for the polymerization reaction Entry9 and Entry 13 in TABLE I.

EXAMPLE 3

[0093] A similar method was used successfully to prepare a chromium(II)chloride complex containing6-[1-{(2,6-dimethylphenyl)imino}ethyl]-2-acetylpyridine. The complex hada light purple color. The amount of tridentate ligand used was 267 mgand CrCl₂, 120 mg, was obtained from Strem Chemical Company.

[0094] This metal complex was used for the polymerization reaction Entry8 in TABLE I.

EXAMPLE 4

[0095] The polymerization reactions were carried out in the followingmanner. All of the solvents such as anhydrous THF, heptane andcyclohexane were purchased from Aldrich Chemical Company and stored overmolecular sieves before use. 1-hexene was obtained as a commercial gradeof Chevron Phillips' NAO's and dried over molecular sieves. MMAO-3A waspurchased from Akzo Nobel.

[0096] For small, low-pressure ethylene polymerization reactions, in aninert, oxygen and moisture free, atmosphere (such as a dry box filledwith nitrogen or argon) the metal-ligand complex, such as achromium-tridentate ligand complex, a medium (polymerization solvent) ifone was used, and a stir-bar were placed in a flask. For amulti-component catalyst system, the second component was also added tothe flask at the same time in the experiments. As already pointed outearlier, the second component also may be added later to a reactor withor without using additional co-catalyst such as aluminum alkyls. Theflask was transferred to a Schlenk manifold and placed under acontinuous ethylene purge. The flask contents were stirred rapidly forseveral minutes to saturate the solvent (such as heptane) with ethyleneand to break apart any small chunks of the complex. A co-catalyst suchas MMAO-3A from Akzo Nobel was added via a syringe while the stirringcontinued. Optionally, a cooling bath could be used to control and/ormaintain the desired reaction temperature. For reactions in which lightolefins (such as butenes) were the primary products, ethylene wascontinuously purged through and out of the reaction flask. For thereactions waxes and/or higher molecular weight polyethylenes (PE) wereproduced, ethylene was added “on demand.”

[0097] For reactions carried out at a pressure higher than about ambientpressure, a one-liter Zipperclave™ reactor fro Autoclave Engineers wasused. The reactor should be clean and dried appropriately. Themetal-ligand complex was dissolved in a small amount of solvent such asmethylene chloride in a breakable thin-glass tube, which was then boundto the stirrer shaft of the reactor. The reactor was then evacuated,charged with a medium if one used and a co-monomer if one is used, and aco-catalyst. If the co-monomer is a gas under ambient conditions, itwould be added via a gas inlet. The olefin (such as ethylene) was thenadded and the stirred shaft was started, thus breaking the breakablethin-glass tube, thus contacting the metal-ligand complex with theco-catalyst and the olefin. For olefins such as ethylene, propylene orbutene which are gases under ambient conditions, they were added throughan inlet tube. It was preferred, particularly for ethylene. that theolefin was added “on demand,” i.e. added enough to maintain a certainpre-determined pressure or pressure profile. The reactor temperature wasmaintained by passing a coolant through and cooling coil inside thereactor. After the desired reaction period was reached, it was moreconvenient to add a deactivating agent to “kill” the catalyst system forproduct work-up. For most reactions, and particularly whenorganoaluminum such as MAO or MMAO co-catalysts were used, an acidifiedmethanol solution was used for this purpose. The product mixtures werethen removed from the reactor, followed by filtration, washing or othercommon product purification techniques. The products were analyzed bygas chromatography (GC) and other analytic techniques or methods knownto those skilled in the art.

[0098] Results from such polymerization reactions are shown in TABLE I.All of the catalysts contained chromium, and MMAO was used as theco-catalyst. Q¹ is nitrogen. Q² and Q³ were both nitrogen for Type 1; Q²was nitrogen and Q³ was oxygen for Type 2. R¹ and R³ (when present inType 1) were represented by FORMULA C with R¹¹ and R¹⁵ shown in theTable. The reactions were carried out at temperatures between 25° C.(ambient temperature) and 100° C. Ethylene pressure was in the range offrom 15 psia (100 kPa) to 415 psia (2,860 kPa).

[0099] Results from polymerizations using a multi-component catalystsystem are shown in TABLE II. Unless otherwise specified, thedesignations and abbreviations are used to indicate the same. See moredetailed descriptions of the two entries below. The metalloceneprecursor C₅(CH₃)₄Si(CH₃)₂N(t-Bu)TiCl₂ was prepared according to themethod in literature TABLE I Polymerization of Ethylene and α-OlefinsUsing Chromium-Tridentate Ligand Complexes Complex P_(ethylene) (psi),Solvent Rxn Prod.^(f) amount comonomer (medium) length Yield (g/g CrEntry Type^(a) R¹¹ R¹⁵ (mg) Al:Cr^(c) (amount)^(d) (ml)^(e) (min) T (°C.) (g) complex) Notes 1 1 H H 5.7 500 15 CyH(40) 30 35 n.d. n.d. rapidexotherm; mostly butene, heavily isomerized to c-and t-2-butene 2 1 Me H6.1 400 15 CyH(40) 60 35 nd. n.d. rapid exotherm, required cooling;mostly 1-butene, 99% purity 3 1 Et H 5.4 500 15 CyH(40) 80 35 n.d. n.d.rapid exotherm, 99% pure 1-butene 4 1 iPr H 4.6 500 15 CyH(40) 30 35n.d. n.d. rapid exotherm, 99% pure 1-butene, small amts. of higherolefins 5 1 t-Bu H 5.2 500 15 CyH(40) 180 25 1.9 370 major product is PB6 1 Me Me 6.7 500 15 CyH(40) 120 35 10.4 1550 C_(max)(GC)˜C₄₈; SchulzFlory constant˜0.96 7 1 Me H 5.1 1100 400 CyH(200) 30 85 n.d. n.d. veryrapid exotherm, 99.6% 1-butene purity, small amt of hexenes, octenes, PB8 2 Me Me 18.0 160 15 heptane(50) 180 25 6.0 330 waxes 9 2 iPr iPr 21.0120 15 heptane(50) 180 25 1.2 60 heavy waxes 10 2 t-Bu H 6.3 500 15heptane(40) 60 25 1.1 180 heavy waxes/PE 11 2 Me Me 5.0 1150 400heptane(200) 60 80 101 20,200 α-olefin waxes, Schulz-Flory K˜0.87 12 2Me Me 4.0 1150 400 heptane(200) 60 100 95 23,800 α-olefin waxes, K˜0.8713 2 iPr iPr 15.0 225 400 heptane(200) 120 60 25.0 1670 heavy waxes, Mn= 750 14 2 Me Me 14.6 160 15, n.a. 360 25 1.8 100 gummy solid; 1-hexenesignificant C₆ incorp. by GC (50 ml) 15 2 Me Me 13.6 260 15, heptane(45)180 25 22.2 1520 waxes; 1-hexene significant C₆ incorp. by GC (9 ml) 162 Me M 13.6 260 15, Heptane(50) 1200 25 35.5 2610 Waxes 1-octadeceneSignificant C₁₈ incorporated (15 ml) 

[0100] TABLE II Entry 17 18 Type (First Component) 1 1 R¹¹ Me IPr R¹⁵ HH Amount (mg) 2.5 2.0 Al:Cr 2000 3000 Second Component g 2 R¹¹ — Me R¹⁵— Me Amount (mg) 4.0 7.5 Al:Metal 1000 600 P_(ethylene) (psia) 15 15Solvent, or medium (ml) Heptane (40) Heptane (50) Reaction time (min) 60240 T (° C.) 30-35 25 Yield (g) 3.61 1.62 Productivity (g/g Cr 900 170complex) Notes PE PE Branching observed^(h) Branching observed^(h)

[0101] For Entry 1, where both R¹¹ and R¹⁵ are hydrogen (H), the buteneproduct contains substantial amount of cis- and trans-2-butenes. ForEntry 14, there was substantial incorporation of 1-hexene in theproducts by analyses. For Entry 15, there was substantial incorporationof 1-hexene in the products by analyses. —For Entry 11, K was about0.87. For Entry 12, K was also about 0.87. For Entry 2, in the C₄olefins, 1-butene was in excess of 99% purity among the butene isomers;some low purity of C₆ products. For Entry 7, in the C₄ olefins, 1-butenewas about 99.6% pure; in the C₆ olefins, 1-hexene was about 93% pure.Entry 3 and Entry 4 also gave 1-butene at 99% purity. Entry 16 showedthe incorporation of 1-C₁₈ olefin.

[0102] It can be seen from these results that a catalyst comprising thechromium metal complexes and an aluminum alkyl co-catalyst, MMAO, wereeffective in both polymerization and co-polymerization. Productscomprising high α-olefin concentrations (such as 1-butene and 1-hexene)were produced when all three coordinating sites are nitrogen and therewas a single ortho-substitution of on the phenyl ring as represented byFORMULA C. When the ortho-substitution was a large t-butyl group,polyethylene was produced.

[0103] Results in TABLE I also showed that catalysts comprising thechromium metal complexes and a suitable aluminum alkyl, MMAO, were veryactive, having good productivity per gram of chromium.

[0104] Entry 17 in TABLE II shows that when a chromium tridentate ligand(type 1, all three coordinating sites were nitrogen) complex was used incombination with a metallocene precursor, polyethylene (wax type) wasobtained with ethylene as the feed. The product was very similar to thatobtained in Entry 15, where 1-hexene was used as a co-monomer. GCanalysis showed branching on the polymer chains.

[0105] Entry 18 in TABLE II shows that when a chromium tridentate ligand(all three coordinating sites were nitrogen) complex was used incombination with a different chromium tridentate ligand (type 2, Q¹ andQ² were nitrogen, Q³, oxygen) complex, polyethylene (wax type) wasobtained with ethylene alone. The product was very similar to thatobtained in Entry 15, where 1-hexene was used as a co-monomer. GCanalysis showed branching on the polymer chains.

[0106] The examples herein are provided only for the purpose ofillustrating the embodied invention. They are not intended and shouldnot be treated as to limit the spirit and scope of the instantinvention, which is defined solely by the specification and claims.

1. A polymerization process for making a product, the polymerizationprocess comprises contacting at least one olefin in a feed, with orwithout a medium, with a catalyst and a co-catalyst, followed byrecovering the product, wherein the catalyst comprises ametal-tridentate ligand complex comprising a transition metal, atridentate ligand having at least two different elements for the threecoordinating sites in the tridentate ligand, the elements are selectedfrom the group consisting of nitrogen, phosphorus, oxygen, and sulfur,and wherein the metal-tridentate ligand complex has a formula as FORMULAB.
 2. The process of claim 1, wherein the olefin in the feed comprisesat least one α-olefin.
 3. The process of claim 2, wherein the transitionmetal (M) consists essentially of an element selected from the groupconsisting of manganese, chromium, vanadium, and mixtures thereof. 4.The process of claim 3, wherein the co-catalyst comprises one or moreorganometallic compounds selected from organoaluminum compound,organoboron compound, organogallium compound, organozinc compound,organocadmium compound, organotin compound, organolithium compound,organosodium compound, organopotassium compound, organorubidiumcompound, organomagnesium compound, organocalcium compound and mixturesthereof; the α-olefin in the feed is selected from the group consistingof ethylene, propylene, 1-butene, butene, cis-2-butene, trans-2-butene,1,3-butadiene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene,1-octene, 1-octadecene, 1,5-hexadiene, 1,4-hexadiene, styrene,o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene,p-t-butylstyrene, and mixtures thereof; and the product comprisesprimarily terminal olefins, which are linear, branched or mixturesthereof.
 5. The process of claim 3, wherein Q¹ and Q² are nitrogen, Q³is oxygen, and R⁴ does not exist; R¹ and R³ are independently selectedfrom C₁ to C₅ alkyl groups; R² is selected from 1-ring aryl groups; R⁵R⁶, and R⁷ are independently selected from H and C₁ to C₅ alkyl groups;and each L is independently selected from F, Cl, Br, I, alkyl, aryl andmixtures thereof.
 6. The process of claim 5, wherein R² has a structureof FORMULA C; R¹², R¹³, and R¹⁴ are H; and R¹¹ and R¹⁵ are selectedindependently from the group consisting of H, methyl, ethyl, n-propyl,and iso-propyl groups.
 7. The process of claim 1, wherein M consistsessentially of an element selected from the group consisting ofchromium, vanadium, manganese, and mixtures thereof; Q¹ and Q² arenitrogen, Q³ is oxygen, and R⁴ does not exist; R¹ and R³ areindependently selected from C₁ to C₅ alkyl groups; R² is selected from1-ring aryl groups; R⁵ R⁶, and R⁷ are independently selected from H andC₁ to C₅ alkyl groups; each L is independently selected from F, Cl, Br,I, alkyl, aryl, and mixtures thereof.
 8. The process of claim 7, whereinR² has a structure of FORMULA C; R¹², R¹³, and R¹⁴ are H; and R¹¹ andR¹⁵ are independently selected from the group consisting of H, methyl,ethyl, n-propyl, and iso-propyl groups.
 9. The process of claim 1,wherein the olefin is selected from ethylene, propylene, 1-butene,1-pentene, 1-hexene, 1-heptene, 1-octene, 1-octadecene, and mixturesthereof; the co-catalyst is selected from at least one aluminum alkylcompound; the transition metal consists essentially of chromium; q is 2;the tridentate ligand is selected from the group consisting of6-[1-{(2,6-dimethylphenyl)imino}ethyl]-2-acetylpyridine,6-[1-{(2,6-dimethylphenyl)imino}ethyl]-2-acetylpyridine, and mixturesthereof; and the product comprises terminal olefins, which are linear,or branched, or mixtures thereof.
 10. A metal-tridentate ligand complexcomprising a structure of FORMULA B.
 11. The metal-tridentate ligandcomplex of claim 10, wherein Q¹ and Q² are nitrogen, Q³ is oxygen, andR⁴ does not exist.
 12. The metal-tridentate ligand complex of claim 11,wherein R² has a structure of FORMULA C.
 13. The metal-tridentate ligandcomplex of claim 12, wherein R¹ and R³ are independently selected fromthe group consisting of C₁ to C₅ alkyls; R¹², R¹³, and R¹⁴ are H; andR¹¹ and R¹⁵ are selected independently from the group consisting of H,methyl, ethyl, n-propyl, and iso-propyl groups.
 14. The metal-tridentateligand complex of claim 13, wherein M consists essentially of an elementselected from the group consisting of, chromium, vanadium, manganese,and mixtures thereof.
 15. The metal-tridentate ligand complex of claim10, wherein M consists essentially of an element selected from the groupconsisting of chromium, vanadium, manganese and mixtures thereof; Q¹ andQ² are nitrogen, Q³ is oxygen, and R⁴ does not exist; R² is selectedfrom the group consisting of C₁ to C₅ alkyl groups, 1-3 ring arylgroups; R⁵ R⁶, and R⁷ are independently selected from H and C₁ to C₅alkyl groups; each L is independently selected from F, Cl, Br, I, alkyl,aryl, and mixtures thereof; and the solvent is selected from the groupconsisting of ether, ester, alcohol, and mixtures thereof.
 16. Themetal-tridentate ligand complex of claim 15, wherein, M consistsessentially of chromium; q is 2; L is chloride; R² has a structure ofFORMULA C, wherein R¹², R¹³, and R¹⁴ are H; and R¹¹ and R¹⁵ are selectedindependently from the group consisting of H, methyl, ethyl, n-propyl,and iso-propyl groups.
 17. A method for preparing the metal-tridentateligand complex of claim 10, the method comprises: contacting a firstcomponent comprising metal (M) with a second component comprising atridentate ligand with a structure of FORMULA A; reacting the firstcomponent with the second component under conditions effective toproduce the metal-tridentate ligand complex; and recovering themetal-tridentate ligand complex.
 18. The method of claim 17, wherein Mconsists essentially of an element selected from the group consisting ofchromium, vanadium, manganese, and mixtures thereof; Q¹ and Q² arenitrogen, Q³ is oxygen, and R⁴ does not exist; R¹ and R³ areindependently selected from C₁ to C₅ alkyl groups; R² has a structure ofFORMULA C, wherein R¹², R¹³, and R¹⁴ are H, and R¹¹ and R¹⁵ areindependently selected from the group consisting of H, methyl, andiso-propyl groups; R⁵ R⁶, and R⁷ are independently selected from H andC₁ to C₅ alkyl groups; and each L is independently selected from F, Cl,Br, I, alkyl, aryl, and mixtures thereof.
 19. A catalyst system forpolymerizing at least one olefin to form a product, the catalyst systemcomprises a metal-tridentate ligand complex having FORMULA B, and aco-catalyst consisting essentially of at least one organometalliccompound.
 20. The catalyst system of claim 19, wherein the olefin isselected from the group consisting of ethylene, propylene, 1-butene,cis-2-butene, trans-2-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene,1-nonene, 1-octadecene, 1,5-hexadiene, 1,4-hexadiene, 1,3-hexadiene, andmixtures thereof; the organometallic compound is selected from the groupconsisting of organoaluminum compound, organoboron compound,organogallium compound, organotin compound, organozinc compound,organocadmium compound, organolithium compound, organosodium compound,organopotassium compound, organorubidium compound, organomagnesiumcompound, organocalcium compound and mixtures thereof; the productcomprises α-olefins, linear, branched or mixtures thereof; M is selectedfrom the group consisting of chromium, vanadium, manganese, and mixturesthereof; Q¹ and Q² are nitrogen, Q³ is oxygen, and R⁴ does not exist; R¹and R³ are independently selected from C₁ to C₅ alkyl groups or 1-3 ringaryl groups; R² has a structure of FORMULA C; R⁵ R⁶, and R⁷ areindependently selected from H and C₁ to C₅ alkyl groups; and each L isindependently selected from F, Cl, Br, I, alkyl, aryl and mixturesthereof.
 21. The catalyst system of claim 19, wherein the olefin isselected from the group consisting of ethylene, propylene, 1-butene,1-hexene, 1-octadecene, and mixtures thereof; the co-catalyst isselected from MAO, MMAO, and mixtures thereof; the product comprisesterminal olefins, which are linear, branched, or mixtures thereof; themetal consists essentially of chromium; Q¹ and Q² are nitrogen, Q³ isoxygen, and R⁴ does not exist; R¹ and R³ are independently selected fromC₁ to C₅ alkyl groups or 1-3 ring aryl groups; R² has a structure ofFORMULA C, wherein R¹², R¹³, and R¹⁴ are H, and R¹¹ and R¹⁵ areindependently selected from the group consisting of methyl andiso-propyl groups; R⁵ R⁶, and R⁷ are H; and L consists essentially ofCl.
 22. An ethylene dimerization process comprising contacting ethylenein a feed with a catalyst and a co-catalyst under conditions effectiveto produce butene; and recovering butene, wherein the catalyst comprisesa metal-tridentate ligand complex comprising a transition metal, atridentate ligand having nitrogen for all its three coordinating sites,and the metal-tridentate ligand complex has a formula as FORMULA B. 23.The ethylene dimerization process of claim 22, wherein ethylene has apartial pressure in the range of from about 0.1 psia (0.7 kPa) to about2500 psia (17,250 kPa) and the conditions comprise a dimerizationtemperature in the range of from about 0° C. to about 150° C.;
 24. Theethylene dimerization process of claim 23, wherein the transition metalconsists essentially of an element selected from the group consisting ofchromium, vanadium, manganese, and mixtures thereof; and the co-catalystcomprises at least one organometallic compound selected from the groupconsisting of organoaluminum compound, organoboron compound, organotincompound, and mixtures thereof.
 25. The ethylene dimerization process ofclaim 24, wherein the transition metal consists essentially of chromium;q is 2; R¹¹ is selected from the group consisting of methyl, ethyl,n-propyl, and iso-propyl groups; R¹⁵ is H; and the product comprises1-butene of 99% or higher purity among butene isomers.
 26. The ethylenedimerization process of claim 24, wherein the transition metal consistsessentially of chromium; q is 2; R¹¹ and R¹⁵ are both H; and the productcomprises butene isomer mixtures.
 27. A polymeric product, wherein thepolymeric product is produced by contacting a feed comprising at leastone α-olefin with a catalyst and co-catalyst with or without a medium;the polymeric product is characterized by having a Schulz-Flory constant(K) in the range of from about 0.5 to about 0.9; the catalyst comprisesa metal-tridentate ligand complex comprising a transition metal, atridentate ligand having at least two different elements for the threecoordinating sites in the tridentate ligand, the elements are selectedfrom the group consisting of nitrogen, phosphorus, oxygen, and sulfur,and wherein the metal-tridentate ligand complex has a formula as FORMULAB; and the co-catalyst comprises at least one organometallic compoundselected from the group consisting of organoaluminum compound,organoboron compound, organogallium compound, organozinc compound,organocadmium compound, organotin compound, organolithium compound,organosodium compound, organopotassium compound, organorubidiumcompound, organomagnesium compound, organocalcium compound, and mixturesthereof.
 28. The polymeric product of claim 27, wherein the transitionmetal (M) consists essentially of an element selected from the groupconsisting of chromium, vanadium, manganese, and mixtures thereof; Q¹and Q² are nitrogen, Q³ is oxygen, and R⁴ does not exist; R¹ and R³ areindependently selected from C₁ to C₅ alkyl groups; R² is selected from1-ring aryl groups; R⁵ R⁶, and R⁷ are independently selected from H andC₁ to C₅ alkyl groups; each L is independently selected from F, Cl, Br,I, alkyl, aryl and mixtures thereof.
 29. The polymeric product of claim28, wherein the α-olefin in the feed is selected from the groupconsisting of ethylene, propylene, 1-butene, cis-2-butene,trans-2-butene, 1,3-butadiene, 1-pentene, 1-hexene, 1-heptene, 1-octene,1-nonene, 1-octene, 1-octadecene, 1,5-hexadiene, 1,4-hexadiene, styrene,o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene,p-t-butylstyrene, and mixtures thereof; and the product comprisesprimarily terminal olefins, which are linear, branched or mixturesthereof.
 30. A polymerization process for making a product, thepolymerization process comprises contacting at least one olefin selectedfrom ethylene, propylene and mixtures thereof in a feed with amulti-component catalyst system and at least one co-catalyst, followedby recovering the product, wherein the multi-component catalyst systemcomprises (a) at least one first component consisting essentially of anolefin dimerization or trimerization catalyst comprising a firstmetal-tridentate ligand complex, wherein the complex comprises a firsttransition metal, a tridentate ligand having nitrogen for all threecoordinating sites in the tridentate ligand, and wherein themetal-tridentate ligand complex has a formula as FORMULA B; and (b) atleast one second component having a second transition metal selectedfrom the group consisting of a Ziegler-Natta catalyst, a precursor ofthe Ziegler-Natta catalyst, a metallocene, a precursor of themetallocene, a second metal-tridentate ligand complex wherein not allthree coordinating sites are the same, and mixtures thereof.
 31. Thepolymerization process of claim 30, wherein the first transition metalis selected from the group consisting of manganese, chromium, vanadium,nickel, and mixtures thereof; and the second transition metal isselected from the group consisting of titanium, zirconium, hafnium,vanadium, and mixtures thereof.
 32. The polymerization process of claim31, wherein the co-catalyst comprises at least one organometalliccompound selected from the group consisting of organoaluminum compound,organoboron compound, organogallium compound, organozinc compound,organocadmium compound, organotin compound, organolithium compound,organosodium compound, organopotassium compound, organorubidiumcompound, organocesium compound, organomagnesium compound, organocalciumcompound, organostrontium compound, organobarium compound, and mixturesthereof.
 33. The polymerization process of claim 32, wherein the productis characterized by having branching along main polymer chains and isselected from the group consisting of polyethylene (PE), low densitypolyethylene (LDPE), linear low density polyethylene (LLDPE),polypropylene (PP), wax, and mixtures thereof.
 34. A multi-componentcatalyst system comprising: (a) at least one first component consistingessentially an ethylene or propylene dimerization or trimerizationcatalyst comprising a metal-tridentate ligand complex, wherein thecomplex comprises a first transition metal, a tridentate ligand havingnitrogen for all three coordinating sites in the tridentate ligand, andwherein the metal-tridentate ligand complex has a formula as FORMULA B;and (b) at least one second component having a second transition metalselected from the group consisting of a Ziegler-Natta catalyst, aprecursor of the Ziegler-Natta catalyst, a metallocene, a precursor ofthe metallocene, a second metal-tridentate ligand complex wherein notall three coordinating sites are the same, and mixtures thereof.
 35. Themulti-component catalyst system of claim 34, wherein the firsttransition metal is selected from the group consisting of manganese,chromium, vanadium, nickel, and mixtures thereof; and the secondtransition metal is selected from the group consisting of titanium,zirconium, hafnium, vanadium, and mixtures thereof.
 36. Themulti-component catalyst of claim 35, wherein the multi-componentcatalyst system is used in the presence of a co-catalyst comprising atleast one organometallic compound to polymerize ethylene or propyleneinto a product characterized by having branching along main polymerchains and being selected from the group consisting of polyethylene(PE), low density polyethylene (LDPE), linear low density polyethylene(LLDPE), polypropylene (PP), wax, and mixtures thereof.